Hybrid Immunotherapy for Hemophagocytic LymphoHistiocytosis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government.
Read our disclaimer for details.

Despite good progress during the last decade, hemophagocytic lymphohistiocytosis (HLH) remains difficult to treat. Two different treatment regimens have been used successfully. The first one, a treatment regimen based on two drugs called etoposide and dexamethasone, has been used worldwide. The second regimen, based on two drugs called Anti-thymocyte globulin (ATG) and prednisone, has been used mostly at one hospital in Paris, for over 15 years. With either regimen, about three quarters of treated children survive the most difficult time, the first two months after diagnosis. These two different regimens appear to work somewhat differently, and we suspect that combining them may give better results than either regimen alone. We are conducting this clinical trial to test the combination of ATG, dexamethasone, and etoposide for the treatment of HLH.

The purpose of this research study is to find out what effects (good and bad) this drug combination has on you and your HLH.

Hemophagocytic lymphohistiocytosis (HLH) is a rare immunological disorder first recognized almost 70 years ago.(1) Genetic and animal studies have indicated that the familial form of HLH is clearly due to a deficiency of cytotoxic killing. Patients with HLH present with a potentially fatal syndrome of 'hyperimmunity.' These patients have severe inflammation, associated with cytopenias and variably severe bone marrow, liver, or CNS damage. Tissue damage and mortality appear to be due to hypercytokinemia related to persistent immune hyperactivation. An animal model of HLH and correlative human studies all suggest that excessive and abnormal activation of T cells drives the pathophysiology of this disorder, and that suppressing this excessive activation is critical for successful therapy of HLH. It is believed a combination of the two proven induction regimens for hemophagocytic lymphohistiocytosis (HLH) (anti-thymocyte globulin (ATG)- and etoposide-based) will result in response rates and overall survival rates at eight weeks which are comparable or better than the current standard of care (induction therapy per the HLH-94 protocol).

ATG, rabbit (Thymoglobulin, Genzyme) will be dosed at 5 mg/kg/dose, given IV on 5 consecutive days (titrated over 4 to 8 hours).

Other Name: Thymoglobulin

Drug: Etoposide

Etoposide will be dosed at 150mg/m2, given IV. The first dose will be given 7 days (+/- 2 days) after the first dose of ATG, and be given weekly for a total of 7 doses.

Other Names:

Etopophos

Toposar

VePesid

Drug: Methotrexate

Intrathecal Methotrexate and hydrocortisone will be administered to CNS+ patients (CNS+ patients are those patients which have any of the following: elevated CSF (cerebral spinal fluid) protein or white count, seizures, focal or global neurologic deficit, MRI abnormalities consistent with CNS involvement by HLH.) in the following doses: age< 1 yr: 6/8mg (MTX/HC), 1-2 yrs: 8/10mg, 2-3 yrs: 10/12mg, >3 yrs: 12/15 mg. It will be administered (+/- 3 days) on day 7, 14, 21 and 42.

Drug: hydrocortisone

Intrathecal Methotrexate and hydrocortisone will be administered to CNS+ patients (CNS+ patients are those patients which have any of the following: elevated CSF (cerebral spinal fluid) protein or white count, seizures, focal or global neurologic deficit, MRI abnormalities consistent with CNS involvement by HLH.) in the following doses: age< 1 yr: 6/8mg (MTX/HC), 1-2 yrs: 8/10mg, 2-3 yrs: 10/12mg, >3 yrs: 12/15 mg. It will be administered (+/- 3 days) on day 7, 14, 21 and 42.

Drug: Dexamethasone

will be started with the ATG. It will be divided BID, given IV for at least 1 week before switching to PO. Dosing: 20mg/m2/day x7days, 10mg/m2/day x7days, 5mg/m2/day x14days, 2.5mg/m2/day x14days, 1.25mg/m2/day x14days.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:

up to 18 Years (Child, Adult)

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

diagnosis of hemophagocytic lymphohistiocytosis

Patients <18 years of age

The patient must have active disease at the time of enrollment

Patient's legal guardians must sign an Institutional Review Board approved consent form indicating their awareness of the investigational nature and the risks of this study.

Eligible subjects must be enrolled with the protocol coordinating center

Exclusion Criteria:

Recent treatment, within 3 months, with another therapeutic regimen for HLH

Known active malignancy

Known rheumatologic diagnosis which may be the underlying cause of HLH